This invention relates to marking devices, and more particularly, to a workpiece layout tool which is capable of aligning a multiplicity of marking tips to meet a specific design requirement.
In the past, the various devices used for marking have required costly man hours to use in order to maintain the required level of accuracy in the marking of workpieces, especially in the marking of sheet metal used in vehicular transportation and aerospace industries.
By way of example is U.S. Pat. No. 2,618,860, which shows a layout machine for airplane construction. However, the layout machine does not spot a plurality of holes at one time and is not similar to the present invention.
Another example is illustrated in U.S. Pat. No. 3,816,933, which illustrates a precision hole spotting tool. The precision hole spotting tool has a pair of scales laying perpendicularly to each other, one scale being slidable with respect to a body and having a hole in one end. Again, this invention only allows the spotting of one hole at a time.
The third example is shown in U.S. Pat. No. 3,775,857 illustrating a set up tool. The set up tool is comprised of a carriage affixed to the workpiece and a slide bar which is slidably engaged with the carriage. The end of the slide bar has a device for locating a point at which machining is required and thereafter receiving a tool bit for accomplishing the machining operation.
The present invention provides a means for accurately, but quickly locating a multiplicity of points where machining is required, without realigning the tool after each point is marked. A slide housing is engaged with the reference edge of a workpiece, for receiving a slide bar having a multiplicity of holes spaced apart by a predetermined distance along the longitudinal center line of the slide bar. A tab along the outside edge of the slide bar on the underside contacts the reference edge of the workpiece to provide the proper alignment of the slide housing. Once the slide housing is engaged with the edge of the workpiece at a given reference point, the slide bar is inserted until the tab rests against the reference edge of the workpiece and the workpiece is marked at each hole in the slide bar, saving many man hours of time, without sacrificing accuracy of the placement of the marks. Once the marks are inscribed on the workpiece (such as sheet metal), the machine operation can be performed.